Having trouble with pop-up windows and ads for MacKeeper

Question

I've been having trouble with pop-up windows and ads for MacKeeper and similar "services." Tried to download "MPlayerX" a week ago and it all started then. I thought I deleted the file but I'm still having trouble. I've been digging for solutions on here, but nothing I've found on here has worked yet--the VSearch stuff (I think) isn't on my hard drive. Any advice?

Answer 1

You installed a variant of the "VSearch" trojan. Remove it as follows.
This malware has many variants. Anyone else finding this comment should not expect it to be applicable.
Back up all data before proceeding.
Triple-click anywhere in the line below on this page to select it:
/Library/LaunchAgents/com.venus.agent.plist
Right-click or control-click the line and select
          Services ▹ Reveal in Finder (or just Reveal)
from the contextual menu.* A folder should open with an item selected. Drag the selected item to the Trash. You may be prompted for your administrator login password.
Repeat with each of these lines:
/Library/LaunchDaemons/com.venus.daemon.plist
/Library/LaunchDaemons/com.venus.helper.plist
Restart the computer and empty the Trash. Then delete the following items in the same way:
/Library/Application Support/venus
/System/Library/Frameworks/v.framework
The problem may have started when you downloaded and ran an application called "MPlayerX." That's the name of a legitimate free movie player, but the name is also used fraudulently to distribute VSearch. If there is an item with that name in the Applications folder, delete it, and if you wish, replace it with the genuine article from mplayerx.org.
This trojan is often found on illegal websites that traffic in pirated content such as movies. If you, or anyone else who uses the computer, visit such sites and follow prompts to install software, you can expect more of the same, and worse, to follow. Never install any software that you downloaded from a bittorrent, or that was downloaded by someone else from an unknown source.
In the Security & Privacy pane of System Preferences, select the General tab. The radio button marked Anywhere  should not be selected. If it is, click the lock icon to unlock the settings, then select one of the other buttons. After that, don't ignore a warning that you are about to run or install an application from an unknown developer.
Then, still in System Preferences, open the App Store or Software Update pane and check the box marked
          Install system data files and security updates (OS X 10.10 or later)
or
          Download updates automatically (OS X 10.9 or earlier)
if it's not already checked.
*If you don't see the contextual menu item, copy the selected text to the Clipboard by pressing the key combination  command-C. In the Finder, select
          Go ▹ Go to Folder...
from the menu bar and paste into the box that opens by pressing command-V. You won't see what you pasted because a line break is included. Press return.